gma500: Convert PSB LVDS to new output handling

LVDS for PSB now uses psb_intel_encoder and psb_intel_connectors instead of
psb_intel_output. i2c_bus and ddc_bus are moved to lvds_priv. There was also a
pointer to mode_dev (for no obvious reason) that we now get directly from
dev_priv.

Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>